An automotive wiper control apparatus has an infrared emitting unit outside an occupant compartment, a photodetector unit inside the compartment in optical alignment with the infrared emitting unit, and an electric control for automatically controlling the wiper operation in dependence on the state in which infrared rays emitted by the infrared emitting unit through a predetermined area of the windshield are received by the photodetector unit. The photodetector unit has an infrared transmission plate formed of an infrared transmissive material and carrying infrared shielding layers applied in a striped pattern to one surface of the plate. The infrared transmission plate is disposed in front of a plurality of photodetectors so that a contrast is produced on the photodetectors by the infrared rays passing through the uncoated zones of the plate which are free from the infrared shielding layers. The contrast is varied with variation in the quantity of raindrops on the predetermined area of the windshield. The electrical control is responsive to the variation in the contrast to automatically control speed of wiper operation as well as intervals of intermittent wiper operations.